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Wednesday, December 31, 2014

While on the road this summer en route to a collecting site I stopped off at a road cut just north of Avoca, NY on I-390. It is a large cut that exposes rocks of Upper Devonian age (Fransian stage) from the Gardeau formation of the West Falls Group. Much of the fallen rock that is exposed at the base of the cut is barren but I did find occasional fossils. This was perhaps the best specimen I found and is the brachiopod Cariniferella tioga. The oval shape of the shell reminded me of Schizophoria sp. but the radial ribs were too coarse for that ID to be correct. Schizophoria does not have a sulcus on the brachial valve either. It was after I received my copy of the new book "Field Guide to the Devonian Fossils of New York" by Karl Wilson that I realized I had a Cariniferella fossil.

Monday, December 29, 2014

Of the two Graptolites that are common in the Verulam formation (middle Ordovician, Katian/Mohawkian stage)of Ontario, Climacograptus typicalisGeniculograptus typicalis is by far the most common. I've found several pieces of it during my many visits but none are very well preserved. ClimacograptusGeniculograptus typicalis can be distinguished from the similar looking Diplograptus by the upturned "teeth" along the sides of the colony.

Edit 1/4/15 - It has come to my attention that the species Climacograptus typicalis has since been renamed to Geniculograptus typicalis, Thanks to the person who runs the "Dry Dredgers" handle on Facebook. They also provided the following: "Mitchell (1987, p. 381; PDF here: http://www.palass-pubs.org/.../pdf/Vol30/Pages%20353-405.pdfused *Climacograptus typicalis* Hall, 1865 as the type species of his new genus *Geniculograptus*. Subsequent authors have supported the validity of *Geniculograptus*
and it's been used in graptolite publications as recent as one or two years ago (e.g. Cooper et al 2012; PDF here: http://www.researchgate.net/.../file/3deec527ea87992c1f.pdf

Saturday, December 27, 2014

Graptolites are a colonial organism similar to Corals and Bryozoans and they are also important index fossils used to help date the rocks they are found in. In the Verulam formation (middle Ordovician, Katian/Mohawkian stage) of Ontario, Canada they are found as black carbon films on the grey limestone rock. Below is Diplograptus amplexicaulis, one of two species that is known from the formation. It formed straight, needle like colonies with edges that look like a saw tooth. Each of the "teeth" was an individual animals home and the colony grew by budding at the tip to make the whole group longer. Because the fossils are preserved only as carbon films it is hard to get good clear examples as they flake or rub off very easily.

Sunday, December 21, 2014

I've only recently become proficient enough to recognize Spinocyrtia brachiopods apart from Mediospirifers when collecting the middle Devonian in New York. When I saw the fossils below for the first time, though, I knew they looked familiar. They are Spinocyrtia elburzensis from Jebel Oufatene near Alnif in Morocco and they come from middle Devonian aged rocks (Emsian stage). They have a very striking resemblance to S. granulosa which is found in the Givetian stage rocks of New York.

I posted pictures of these fossils onto the Fossil Forum and a couple of knowledgeable people gave me some info. One of them is an expert in Devonian Spiriferids who indicated that S. granulosa is an immigrant into the Appalachian Basin during the Givetian and sticks around into the Fransian stage. So it is possible that S. elburzensis is the predecessor of S. granulosa.

Wednesday, December 17, 2014

I've been wanting to get some Devonian fossils from Morocco that were not trilobites for some time now. My thought was that they had to exist out there in the desert but that they weree just being overlooked by the collectors since they could make more money selling trilobites. Lucky for me that I stumbled upon a dealer on Facebook who did have some brachiopods from Jebel Issomour for sale and I snapped them up.

This is Glyptogypa multiplicata and comes from rocks dated to the Eifelian stage of the Devonian period.

About Me

I'm a 40-something, life long student of Geology living in Philadelphia. My interests include Photography, Architecture and History among other things. When not cleaning my recent finds you'll find me in my backyard Hybridizing Daylilies or working in my garden. This Blog is an outlet for me to express my interest in fossils, catalog my collection and coalesce my thoughts and research into a useful medium.